Rotary internal combustion engine

ABSTRACT

A plurality of equally spaced, notch-like recesses are formed about the inner circumference of a circular disc-shaped cavity formed in a stationary engine casing. Partial circular cavities are formed in the main disc eccentrically with respect to its axis of rotation. In each partial cavity a revolving lever wheel carries a plurality of radial arms adapted to engage the recesses in the casing. As the main disc rotates, the lever wheels rotate in the opposite direction, like planetary gears, with the respective ends of the arms successively engaging the recesses in the housing. Each combustion chamber is defined by the volume enclosed by two adjacent arms and the opposite portions of the sidewalls of the casing and lever wheel cavities. During combustion each lever wheel pivots about the end of the arm engaging a recess in the casing, providing a lever force which acts upon the rotational axis of the main disc.

tlniteai @tates yatent 1191 Lee [451 ire/6. it, 11975 ROTARY INTERNAL COMBUSTION Primary Examiner-C. J. Husar ENGXNE Assistant Examiner-Leonard Smith [75] Inventor: Choong-Gil Lee, Honolulu, Hawaii ggggg Agent or Flrm Lane Altken Dunner & [73] Assignee: Lee & Lee Research Laboratories,

Honolulu, Hawaii 57 ABMRACT [22] Filed: Aug. 22, 1973 A plurality of equally spaced, notch-like recesses are formed about the inner circumference of a circular [21] Appl' 390406 disc-shaped cavity formed in a stationary engine casing. Partial circular cavities are formed in the main [52] U.S. Cl l23/8.45, 418/61 R, 418/225 disc eccentrically with respect to its axis of rotation. in [51] int. Cl. F02!) 55/14 each partial cavity a revolving lever wheel carries a [58] Field of Search 418/54, 58, 61, 209, 225, plurality of radial arms adapted to engage the recesses 418/161, 164, 165, 175; 123/807, 8.45, 8.47 in the casing. As the main disc rotates, the lever wheels rotate in the opposite direction, like planetary [56] References Cited gears, with the respective ends of the arms succes- UNITED STATES PATENTS sively engaging the recesses in the housing. Each com- 949,605 2/1910 Taylor 418/165 busto".chamber defined by i inclosed by 2478 924 M949 Johnson n 123/8 45 X two ad acent arms and the opposite portions of the 312411745 3/l966 Williams 418/61 R sidewalls of the Casing and ever Wheel Cavitiesing combustion each lever wheel pivots about the end FOREXGN PATENTS OR APPLICATIONS of the arm engaging a recess in the casing, providing a 606,687 6/ 926 a ce 413/225 lever force which acts upon the rotational axis of the 900,028 12/1953 Germany l23/8.47 i disc l45,l49 6/1920 Great Britain .i 123/847 8 Claims, 7 Drawing Figures db-- IO 34 I4 32 24 1 .1 l4 at u a I 200 32 48 as l 3o 32 -34 46-- r 14 4,4 42 4 I I4 I Il I 1 I 34 3. a

I ROTARY INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION The invention relates generally to the field of internal combustion engines, and more particularly to rotary internal combustion engines.

The success of the Wankel engine has generated increasing interest in diverse types of rotary internal combustion engines. The attraction of the rotary engine stems primarily from its theoretical efficiency and simplicity, compared to reciprocating internal combustion engines. Reciprocating piston engines require periodic acceleration and deceleration of the pistons as they move back and forth in their cylinders. Because the pistons have inertia, some amount of energy is lost. However, rotary piston engines sustain their angular momentum; the piston does not undergo an abrupt change of linear direction. To obtain a rotational output from an engine having reciprocating pistons, a crankshaft and connecting rods are required while in the rotary engine these parts are eliminated because the combustion chamber itself rotates about the output axis thus creating an output torque in a more direct fashion.

U.S. Pat. Nos. 726,896 to Franzen and 3,241,745 to Williams, and German Pat. No. 900,028 are of interest by way of background because they show rotary engines (steam, gasoline and diesel, respectively) employing eccentric piston wheels. Each piston wheel has a plurality of radial arms with piston ends which engage radial bores in an outer rotatable casing. In all of these systems the compression chambers are formed solely between the piston ends of the radial arms and the bores. Thus the size of each piston chamber is limited by the ability of each piston end to reciprocate in the bores while the axle on which the piston arm is carried revolves with respect to the casing in which the bores are formed.

SUMMARY OF THE INVENTION The general purpose of the invention is to simplify and improve rotary internal combustion engines. A more specific aim of the invention is to convert the power of internal combustion to a lever force acting upon an output axis by means of levers revolving about a second axis displaced from the output axis, thus permitting the direct application of torque to the output axis.

The applicant has discovered that these and other objects can be accomplished by forming combustion chambers between adjacent radial arms of a multiarmed, planetary lever wheel such that combustion tends to pivot the lever wheel about an engaged notch in a stationary engine casing. In particular, the rotary internal combustion engine according to the invention includes a plurality of equal spaced, notch-like recesses formed about the inner circumference of a disc-shaped central cavity formed in a stationary block or casing. A coaxial main disc is sealingly rotatable within the central casing cavity. Partial circular cavities for the lever wheels are formed in the main disc eccentrically with respect to its axis of rotation. In each partial cavity a lever wheel is mounted for rotation. The end of each radial arm of each lever wheel is adapted to sealingly engage the recesses formed in the casing. As the main disc rotates about its axis, the lever wheels rotate epicyclically in the opposite direction, like planetary gears, with the ends of the arms successively engaging the recesses in the casing.

Each combustion chamber is defined by the volume encompassed by two adjacent arms of a lever wheel and the opposite portions of the sidewalls of the casing and lever wheel cavities. During combustion, the lever wheel pivots about the end of the arm engaging the adjacent recess in the casing cavity. The lever force thus produced acts upon the displaced rotational axis of the lever wheel providing a direct resultant torque about the central output axis of the main disc. Intake and compression occur while the end of the adjacent arm engages the preceding recess. Because the partial lever wheel cavity is truncated by the circumference of the main disc, the volume defined between the two adjacent arms of the lever wheel and. the sidewalls of the partial cavity and casing cavity varies, and this variation in volume is harnessed to provide the compression and power strokes of the combustion cycle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of a side view partially in section of an embodiment of a rotary internal combustion engine according to the invention.

FIG. 2 is a schematic representation of a sectional view taken along lines 22 of FIG. 1 illustrating the main disc and lever wheels in more detail.

FIGS. 3-7 are schematic representations of views similar to that of FIG. 2 illustrating different consecutive phases of the combustion cycle as the main disc rotates.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 11 and 2, the rotary internal combustion engine according to the invention includes a stationary disc-shaped motor housing or casing 10 having a disc-shaped central inner cavity 12. Eight radial recesses or notches 14 formed in the casing 10 are equally spaced about the inner circumference of the cavity 12. Thus the respective center lines of each ad jacent pair of notches 14 are angularly displaced from each other by 45 with respect to the axis of the cavity 12. A main disc or rotor 16 having approximately the same dimensions as the disc-shaped cavity 12 is disposed therein and mounted for rotation on an output axle 1% extending rotatably through the casing 10 coincident with the axis of the cavity 12. The axle 118 is rigidly connected to the rotor 16 for rotation therewith and forms the output drive shaft of the engine. A pair of partial circular cavities 20 and 22 of equal diameter are formed in the rotor 16 with their central axes 20a and 22a, respectively, at the same radial distance from the axis of rotation of the rotor 16. The rotor 16 is received in the cavity 12 of the casing 10 with close tolerance so as to continuously seal the cavities 20 and 22 against the inner cylindrical periphery of the cavity 12, as shown in FIG. 1. The partial cavities 20 and 22 are centered on opposite sides of the axle 18 such that the axis of the partial cavities 20 and 22 and the axis of the rotor 16 lie in the same plane. The dimensions and the positioning of each partial cavity are such that the radial distance from the geometrical center of the cavity to the circumference of the rotor 1.6 is substantially less than the radius of the partial cavity. In addition, the distance from the geometrical centers of the cavities 20 and 22 to the axle 18 is greater than their radii. The outermost point on the geometrical circumference of each cavity measured radially from the axis of the rotor 16 lies on the dashed circular reference line 24 as the rotor 16 rotates. The back wall of each notch 14 also coincides with the line 24.

Lever wheels 26 and 28 are mounted for rotation respectively about the geometrical axes 20a and 22a of the partial cavities 20 and 22. Each lever wheel 26, 28 comprises three equally spaced radial arms 30 joined at the center to form a generally Y-shaped configuration. The outer end of each radial arm 30 terminates in a notch-engaging end portion 32 with an interior recess 32a. The radial length of each arm 30, including the end portion 32, coincides with the radius of the respective cavity 20 or 22, and the end portion is sealingly slidable along the sidewall of the partial cavity.

As shown in FIG. 2, each end portion 32 is adapted to successively engage the notches 14. As the rotor 16 rotates, teh arm 30 whose end portion 32 is engaging a notch 14, pivots about the notch causing counterrotation of the lever wheel 26 or 28. As rotation continues, the respective end portions 32 engage successive notches 14. The dimensions of the lever wheels 26 and 28 are related to the diameter of the rotor 16 and the number of equally spaced notches 14 such that as one of the end portions 32 is moving out of engagement with a notch 14, the next, adjacent end portion 32 is simultaneously moving into engagement with the next notch along the circumference of the inner central cavity 12.

The fuel intake system includes a plurality of ducts 34 formed through the casing located adjacent to the notches 14 respectively. The outer end of each duct is adapted to be connected to a suitable intake manifold for receiving a pressurized combustible mixture. The inner end of each duct 34 terminates in a port 34a flush with the circumference of the cavity 12. The main rotor 16 has a pair of short, complementary intake ducts 36 each located at a position closely adjacent to the point where the outer sidewall of the rotor 16 meets the inner sidewall of the respective cavity or 22. Each duct 36 terminates at one end in a port 36a in the outer sidewall of the rotor 16 for periodic registration with port 34a of the intake duct 34 in the casing 10. The other end of each duct 36 is in communication with the interior of the respective cavity 20 or 22. The registering ports 34a and 3611 are located axially (in a direction parallel to the axis of rotation) away from the cavities 20 and 22. That is, the rotor ducts 36 are skewed slightly relative to the plane of the rotor 36. Thus, the casing port 34a is sealed off by the sidewall of the rotor 16 at all times except those when the ports 34a and 36a are in registration.

Exhaust ports 38 are formed through the body of rotor 16 parallel to its axis at a predetermined position just within the circumference of the partial cavities (20 and 22). The exhaust ports 38, as shown in FIG. 1, are in communication with an annular exhaust manifold 40 vented to the outside of the casing 10. A pair of auxiliary-exhaust ducts 42 (FIG. 2) terminate respectively at one end in a port 44 formed through the outer sidewall of the rotor 16 and at the other end in a port 46 communicating with the interior of the cavity 20 or 22, respectively, at a position along the sidewall of the cavity closely adjacent to the position of the corresponding exhaust port 38. The function of the auxiliary exhaust duct 42 is to relieve exhaust gases trapped in disengaged notches 14 via the port 46.

Spark plugs 48 for igniting the compressed combustible mixture are located respectively to one side of each notch 14. The engine casing 10 also includes an oil chamber 50 formed about the axis of rotation of the rotor 16 on either side thereof and suitable ducting for a coolant such as water, as illustrated by chambers 52 formed in the casing 10 toward its outer periphery.

The principle of operation is illustrated in FIGS. 3-7, showing five consecutive positions of the lever wheel 26 during rotation of the rotor 16. The angular orientation of the casing 10 is the same in each figure. Only lever wheel 26 is illustrated as lever wheel 28 is simultaneously undergoing an identical combustion cycle, presenting an additive equal torque in the same angular direction. For convenience in identifying the notches l4 and the arms of the lever wheel 26, the notches are designated 14a, 14b, etc., and the arms are designated 30a, 30b and 30c. The main rotor 16 rotates counterclockwise and the lever wheel 26 rotates counterclockwise like planetary gear.

The volumes defined between each adjacent pair of arms 30 on the lever wheel 26 form three separate, rotating chambers A, B and C, sealed from each other. For any one of the chambers, while the end portions 32 of the adjacent arms 30 are both in sealing contact with the circular sidewall of the cavity 20, the volume contained between the arms 30 and the sidewall of the cavity 20 remains constant. Thus in FIG. 3 the chambers A and B have equal volume. However, chamber C has reduced volume by virtue of the fact that the sidewall of the cavity 12 of the casing instead of the sidewall of the lever wheel cavity 20 defines the volume of the chamber along with the adjacent legs 30b and 30c. The combustion cycle is exactly the same for each of the chambers A, B and C except that they are out of phase with each other. Therefore it will suffice to describe the cycle for one of the chambers, B, although it will be appreciated that corresponding events are taking place at successively delayed times in the other two chambers, A and C.

At the beginning of the cycle for chamber B, the end of the lever arm 30a has just passed the exhaust port 38, and arms 30b and 30c are simultaneously in contact with notches 14b and 14a respectively. At this time the inlet ports 34a and 36a are in registration and a pressurized combustible mixture is injected into the chamber B. In FIG. 4, the casing inlet port 340 is sealed off, and chamber B is undergoing a reduction in volume while the whole lever wheel 26 is pivoting on the arm 30b engaging the notch 14b. The progressively decreasing volume compresses the combustible mixture which has become trapped within the chamber B because the inlet ports are no longer in registration. In FIG. 5 chamber B has been reduced to its smallest volume, as radial arm 30a engages the next notch 14c with arm 3011 still in contact with the preceding notch 1412. It is at this point that ignition in chamber B takes place by means of the spark plug 48. It should be noted that chamber A is now in the fuel intake position as was chamber B in FIG. 3.

FIG. 6 illustrates the chamber B power stroke during which the chamber B is increasing in volume under the action of the pressure created by combustion. Because the notch 14c of the casing 10 is stationary, the force of combustion tends to pivot the lever wheel 26 about the point of contact 54 of the end of the arm 30a and the notch 140. Of course, the point of contact 54 is constantly changing because the axle of the lever wheel 26 is connected to the main disc 16. As a result of the force of compression acting upon the lever arms 30a and 30b, a resultant torque is applied to the main disc 16, causing rotation thereof.

As soon as the chamber B has regained its full volume, as shown in FIG. 7, the radial arm 30b sweeps over the exhaust port 38, thus venting the chamber B. The hot, spent gases in the chamber B are still at a much higher pressure than atmospheric and most of the exhaust can be accomplished without reducing the volume of the chamber B or requiring scavenging devices.

If scavenging is necessary in a particular embodiment of the system, a scavenging fan can be associated with the exhaust manifold 40 (FIG. ll). Alternatively, altering the location of the registering inlet ports Ma and 36a can also enhance exhaust extraction by arranging for the fresh mixture to be blown into the partially exhausted chamber while the chamber is still in communication with the exahust port 38. For example, the inlet port 36a could be located parallel to the exhaust port (38) approximately in the position indicated by the circular dashed lines 36a in FIG. 7.

Those skilled in the art of internal combustion engines will recognize that many of the design aspects of the illustrated embodiments may be altered or combined with other features to accomplish various performance objectives without departing substantively from the principle and scope of the invention as indicated by the appended claims. For example, the rela tive diameters of the main disc 16 and the lever wheel cavities and 22 can be varied. The shape of the radial arms of the lever wheels can be changed to effect an increase or decrease in the compression ratio. While, in the illustrated embodiment, the sides of adjacent arms of the lever wheels form concave walls, the arms can be broadened to any degree consistent with the objective of clearing the sidewall of the casing cavity l2 and the edges of the notches 14. If desired, adjacent sides of the lever wheel arms may form convex walls conforming closely with the circumference of the casing cavity 12. The contours of the notches represent another design perameter which may be varied depending on the particular geometry of the ends of the lever wheel arms. Any suitable pump, fan or compressor apparatus can be used to force a combustible air-fuel mixture into the chambers during the intake phase. In addition, while the specific engine illustrated herein operates on the two-cycle gasoline engine principle, the system is equally applicable with suitable modifications to two or four-cycle, gasoline, gas or diesel operation.

I claim:

1. An internal combustion rotary engine, comprising a housing having a circular interior cavity with equally spaced recessed notches formed about the circumference thereof, a disc-shaped rotor disposed coaxially within said housing cavity for sealing rotation therein, said rotor having a pair of opposite radial recesses formed in the circumference thereof, each having a partial circular cross-section in a plane perpendicular to the axis of rotation of said rotor, a lever wheel being disposed for rotation within each said recess of said rotor about the geometrical axis of each said recess, said lever wheel having a plurality of equally spaced ra' dial arms extending into sealing slidable contact with the sidewall of the corresponding rotor recess, the ends of respective ones of said radial arms being formed to engage successive ones of said notches, a plurality of rotatable combustion chambers being defined between adjacent ones of said radial arms, means for introducing a combustible mixture into the interior of each said rotor recess, ignition means mounted in said housing between each pair of adjacent notches for causing ignition of said combustible mixture in the reduced volume defined between the inside of said housing cavity and two adjacent radial arms whose ends are simultaneously engaging consecutive notches, whereby the force of combustion tends to pivot said lever wheel about the end of one of its radial arms engaging one of said notches to drive the geometrical axis of rotation of said lever wheel about the rotational axis of said rotor, and means for relieving the exhaust gases from the interior of said rotor recess.

2. A rotary internal combustion engine, comprising engine casing means defining a cavity of circular crosssection and a plurality of equally spaced recesses formed through the circumference of said cavity about the central axis thereof, a rotor disposed within said cavity for rotation about said central axis, said rotor having means defining a partial disc-shaped cavity with a geometrical axis displaced radially from said central axis, such that a portion of the sidewall of said partial disc-shaped cavity is formed by the sidewall of said cavity defined by said casing means, a lever wheel mounted for rotation in said partial cavity about said geometrical axis, said lever wheel having a plurality of equally spaced radial arms extending to the geometrical circumference of said partial disc-shaped cavity, the ends of said arms formed respectively to engage successive ones of said recesses under relative rotation of said rotor and said casing means, separate, rotatable combustion chambers being defined between adjacent ones of said arms, means for introducing a combustible mixture into the volume defined by a pair of adjacent arms and the sidewall of said partial disc-shaped cavity at a first predetermined point in said relative rotation, means for igniting said mixture at a second predetermined point in said relative rotation when said introduced mixture has been compressed, and means for exhausting the combusted mixture at a third predetermined point in said relative rotation.

3. The engine of claim 2, wherein said radial arms number three.

4. The engine of claim 2, wherein said means for introducing a combustible mixture includes an inlet duct formed in said rotor from the circumference of said cavity defined by said casing means to the interior of said partial disc-shaped cavity, and said casing means further defining duct means terminating in an inlet port located along the periphery of said casing cavity between two adjacent recesses for registration with said inlet duct at said first predetermined point.

5. The engine of claim 2, wherein said rotor comprises a disc-shaped member mounted for rotation within said casing cavity with an outer circumference having approximately the same dimensions as the easby said igniting means taking place in the reduced volume defined between said two adjacent arms and the sidewall of said cavity defined by said casing means.

7. The engine of claim 6, wherein said exhausting means includes an exhaust port formed through one of the opposed circular surfaces of said partial discshaped cavity at a predetermined location to vent the interior of said partial cavity, said third predetermined point approximately corresponding to the angular posicavity. 

1. An internal combustion rotary engine, comprising a housing having a circular interior cavity with equally spaced recessed notches formed about the circumference thereof, a disc-shaped rotor disposed coaxially within said housing cavity for sealing rotation therein, said rotor having a pair of opposite radial recesses formed in the circumference thereof, each having a partial circular cross-section in a plane perpendicular to the axis of rotation of said rotor, a lever wheel being disposed for rotation within each said recess of said rotor about the geometrical axis of each said recess, said lever wheel having a plurality of equally spaced radial arms extending into sealing slidable contact with the sidewall of the corresponding rotor recess, the ends of respective ones of said radial arms being formed to engage successive ones of said notches, a plurality of rotatable combustion chambers being defined between adjacent ones of said radial arms, means for introducing a combustible mixture into the interior of each said rotor recess, ignition means mounted in said housing between each pair of adjacent notches for causing ignition of said combustible mixture in the reduced volume defined between the inside of said housing cavity and two adjacent radial arms whose ends are simultaneously engaging consecutive notches, whereby the force of combustion tends to pivot said lever wheel about the end of one of its radial arms engaging one of said notches to drive the geometrical axis of rotation of said lever wheel about the rotational axis of said rotor, and means for relieving the exhaust gasEs from the interior of said rotor recess.
 2. A rotary internal combustion engine, comprising engine casing means defining a cavity of circular cross-section and a plurality of equally spaced recesses formed through the circumference of said cavity about the central axis thereof, a rotor disposed within said cavity for rotation about said central axis, said rotor having means defining a partial disc-shaped cavity with a geometrical axis displaced radially from said central axis, such that a portion of the sidewall of said partial disc-shaped cavity is formed by the sidewall of said cavity defined by said casing means, a lever wheel mounted for rotation in said partial cavity about said geometrical axis, said lever wheel having a plurality of equally spaced radial arms extending to the geometrical circumference of said partial disc-shaped cavity, the ends of said arms formed respectively to engage successive ones of said recesses under relative rotation of said rotor and said casing means, separate, rotatable combustion chambers being defined between adjacent ones of said arms, means for introducing a combustible mixture into the volume defined by a pair of adjacent arms and the sidewall of said partial disc-shaped cavity at a first predetermined point in said relative rotation, means for igniting said mixture at a second predetermined point in said relative rotation when said introduced mixture has been compressed, and means for exhausting the combusted mixture at a third predetermined point in said relative rotation.
 3. The engine of claim 2, wherein said radial arms number three.
 4. The engine of claim 2, wherein said means for introducing a combustible mixture includes an inlet duct formed in said rotor from the circumference of said cavity defined by said casing means to the interior of said partial disc-shaped cavity, and said casing means further defining duct means terminating in an inlet port located along the periphery of said casing cavity between two adjacent recesses for registration with said inlet duct at said first predetermined point.
 5. The engine of claim 2, wherein said rotor comprises a disc-shaped member mounted for rotation within said casing cavity with an outer circumference having approximately the same dimensions as the casing cavity, said partial disc-shaped cavity being formed in said disc.
 6. The engine of claim 2, wherein said second predetermined point corresponds approximately to simultaneous engagement of consecutive ones of said recesses by the ends of two adjacent arms, the ignition caused by said igniting means taking place in the reduced volume defined between said two adjacent arms and the sidewall of said cavity defined by said casing means.
 7. The engine of claim 6, wherein said exhausting means includes an exhaust port formed through one of the opposed circular surfaces of said partial disc-shaped cavity at a predetermined location to vent the interior of said partial cavity, said third predetermined point approximately corresponding to the angular position where an ignited chamber has returned to full volume following a power stroke.
 8. The engine of claim 7, wherein said rotor includes means defining an auxiliary exhaust duct for venting gases trapped in said recesses after passage of said lever wheel to said exhaust port via said partial disc-shaped cavity. 